US20100027513A1 - Base Station Device and Control Method for the Same - Google Patents
Base Station Device and Control Method for the Same Download PDFInfo
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- US20100027513A1 US20100027513A1 US12/159,087 US15908706A US2010027513A1 US 20100027513 A1 US20100027513 A1 US 20100027513A1 US 15908706 A US15908706 A US 15908706A US 2010027513 A1 US2010027513 A1 US 2010027513A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
- H04W16/02—Resource partitioning among network components, e.g. reuse partitioning
- H04W16/06—Hybrid resource partitioning, e.g. channel borrowing
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/04—Wireless resource allocation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W76/00—Connection management
- H04W76/10—Connection setup
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
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Abstract
A base station device (12) is capable of multiplex communications with a plurality of mobile station devices using space division multiple access on a communication channel at a specified carrier frequency, receives a start request for multiplex communications from the mobile station device in accordance with a presence or absence of another communication signal on the communication channel, and allocates the communication channel to the mobile station device that has made the start request in response to the start request. The base station device (12) includes a transmission control unit (22) for performing intermittent transmission of communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices.
Description
- The present invention relates to a base station device and a control method for the base station device, and more particularly relates to a base station device and a control method for the base station device for performing multiplex communications with a plurality of mobile station devices using space division multiple access at a specified carrier frequency.
- Space division multiple access (SDMA) is a wireless communication technique in which the same carrier frequency is spatially divided, and the utilization efficiency of the frequency is increased. In mobile communication systems using SDMA, an adaptive array antenna is installed in a base station device, transmission beams having respectively different directivity patterns are formed for each of the mobile station devices, and radio waves are simultaneously transmitted to each of the mobile station devices. When the base station device transmits signals to the mobile station device, the base station device performs a control so that transmission beams are directed toward the mobile station device as the transmission partner by adaptive beamforming, and the null points of the directivity pattern are directed toward the mobile station devices other than the transmission partner by adaptive null steering. Similarly, when the base station device receives signals from the mobile station devices as well, the reception beams are directed toward the mobile station device as the reception counterpart (in the desired wave direction) by adaptive beamforming, and the null points of the directivity pattern are directed toward the mobile station devices other than the reception counterpart (in the interference wave direction) by adaptive null steering. Accordingly, SDMA mobile communication systems increase the utilization efficiency of the frequency by simultaneously allocating the same carrier frequency to a plurality of mobile station devices while maintaining communication quality between the base station device and mobile station devices.
- When the base station device assigns a communication channel according to a carrier frequency already in use in communication with the first mobile station device to the second mobile station device by spatial multiplexing, the base station device notifies the second mobile station device of this communication channel to be used in communication with the second mobile station device. The second mobile station device performs a carrier sense (interference wave measurement) with respect to this communication channel notified from the base station device. Carrier sense refers to an investigation of whether or not an interference wave signal having a certain power or greater is received on the designated communication channel. If an interference wave signal is detected on the communication channel, communications cannot be started in this communication channel. The reason is that a risk is presented that the communication quality of the second mobile station device will deteriorate by the interference wave, and a risk is also presented that the communications of the second mobile station device will interfere with the communications of other communication devices.
- The base station device in communication with the first mobile station device via the communication channel performs a control for directing the transmission beam toward the first mobile station device by adaptive beamforming; however, a control for directing the null points of the directivity pattern toward the other mobile station devices including the second mobile station device is not performed. When the second mobile station device performs a carrier sense in this state, the second mobile station device detects the communication signals transmitted from the base station device toward the first mobile station device as interference wave signals; accordingly, the carrier sense cannot be passed. In this respect, a technique is disclosed in
patent document 1 shown below for reliably causing the second mobile station device to pass a carrier sense by stopping the transmission of communication signals to the first mobile station device until carrier sensing for the communication channel is completed by the second mobile station device after the base station device has notified the second mobile station device of the communication channel. - [Patent Document 1] Japanese Laid-Open Patent Application No. 2004-248001.
- Furthermore, a method is also conceivable in which the base station device determines the direction of the second mobile station device on the basis of a connection request signal or the like from the second mobile station device, and performs null control in this direction. However, in cases where the frequency of the connection request signal or the like and that of the communication channel differ, the precision of null control for the second mobile station device is poor, and it may not be possible to pass a carrier sense. Accordingly, it is more desirable to stop the transmission of communication signals to the first mobile station device completely.
- In actual SDMA mobile communication systems, the timing at which a carrier sense is started and the time required for the carrier sense differ according to the type of the mobile station devices. Accordingly, in the above-mentioned conventional technique, it is necessary for the base station device to set the transmission stopping period for the first mobile station device at a certain length in order to allow any type of mobile station device to pass a carrier sense.
- However, if the base station device stops transmission to the first mobile station device for a long period of time, a risk is presented that the first mobile station device will detect this as a frame error, and will initiate a handover. If this occurs, the communication channel used in communication with the first mobile station device by the base station device becomes an idle channel, and spatial multiplex communications end up being unsuccessful in this communication channel.
- The present invention was devised in light of the abovementioned conventional problems. It is an object of the present invention to provide a base station device and a control method for the base station device which can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and improve the success rate of space division multiple allocation.
- In order to achieve the abovementioned object, a base station device according to the present invention is a base station device which is capable of multiplex communications with a plurality of mobile station devices using space division multiple access on a communication channel at a specified carrier frequency, receives a start request for multiplex communications from the mobile station device in accordance with a presence or absence of another communication signal on the communication channel, and allocates the communication channel to the mobile station device that has made the start request in response to the start request, the base station device includes transmission control means for performing intermittent transmission of communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices.
- Furthermore, the base station device control method according to the present invention is a control method for a base station device which is capable of multiplex communications with a plurality of mobile station devices using space division multiple access on a communication channel at a specified carrier frequency, receives a start request for multiplex communications from the mobile station device in accordance with a presence or absence of another communication signal on the communication channel, and allocates the communication channel to the mobile station device that has made the start request in response to the start request, wherein communication signals are intermittently transmitted to the mobile station device already in communication on the communication channel among the plurality of mobile station devices.
- According to the present invention, the occurrence of frame errors can be suppressed to a greater extent than in a case in which the transmission of communication signals by the base station device is stopped for a long period of time, and the mobile station device can be caused to perform a carrier sense while the transmission is stopped. Accordingly, the base station device can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and improve the success rate of space division multiple allocation.
- According to another aspect of the present invention, the transmission control means performs the intermittent transmission of the communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices, after notification of the communication channel is provided to the mobile station device that has made the start request. According to such an arrangement, the base station device can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and can improve the success rate of space division multiple allocation, without greatly lowering the throughput of the mobile station device already in communication.
- According to another aspect of the present invention, the base station device further includes transmission pattern storage means for storing a plurality of transmission patterns for the intermittent transmission, wherein the transmission control means retrieves one of the transmission patterns stored in the transmission pattern storage means, and intermittently transmits the communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices, in accordance with this transmission pattern. According to such an arrangement, the base station device can perform transmission control of communication signals on the basis of one of a plurality of intermittent transmission patterns stored beforehand; accordingly, the base station can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and improve the success rate of space division multiple allocation.
- According to another aspect of the present invention, the base station device further includes successful transmission pattern storage means for storing the transmission pattern for the intermittent transmission performed by the transmission control means in association with identification information for the mobile station device that has made the start request, wherein in a case where a start request is again made by the mobile station device that has made the start request, the transmission control means retrieves the transmission pattern stored in the successful transmission pattern storage means in association with identification information for this mobile station device, and intermittently transmits communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices, in accordance with this transmission pattern. According to such an arrangement, the base station device can perform the transmission control of communication signals on the basis of intermittent transmission patterns successful in space division multiple allocation; accordingly, the base station device can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and improve the success rate of space division multiple allocation.
- According to another aspect of the present invention, the transmission pattern includes information specifying a timing at which the transmission of the communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices is stopped, and a period for which the transmission is stopped. According to such an arrangement, the base station device can perform the transmission control of communication signals on the basis of an optimal intermittent transmission pattern prepared beforehand for each type of mobile station device; accordingly, the base station device can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and improve the success rate of space division multiple allocation.
- According to another aspect of the present invention, the transmission control means limits the stopping of the transmission of the communication signals on the communication channel until a predetermined period of time has elapsed after once stopping the transmission of the communication signals on the communication channel. Furthermore, the transmission control means may initiate transmission after once stopping the transmission of the communication signals on the communication channel, and stop the transmission on a communication channel differing from the communication channel on which the transmission of the communication signals was once stopped when the transmission is again stopped. According to such an arrangement, the base station device can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and improve the success rate of space division multiple allocation, without greatly lowering the throughput of the mobile station device already in communication.
- According to another aspect of the present invention, the base station device is capable of multiplex communications with the plurality of mobile station devices using time division multiple access and space division multiple access; the base station device includes slot for multiplexing selection means for selecting any one of time slots already allocated to at least one of the mobile station devices other than the mobile station device that has made the start request as a slot for multiplexing that is allocated to the mobile station device that has made the start request; and the communication channel is specified by the slot for multiplexing selected by the slot for multiplexing selection means and the specified carrier frequency. According to such an arrangement, the base station device using time division multiple access can suppress the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation, and improve the success rate of space division multiple allocation.
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FIG. 1 is a configuration diagram of a mobile communication system according to an embodiment of the present invention; -
FIG. 2 is a block diagram of a base station device according to an embodiment of the present invention; -
FIG. 3 is a diagram showing an example of a transmission pattern storage unit; -
FIG. 4 is a diagram showing an example of a successful transmission pattern storage unit; -
FIG. 5 is a diagram showing a relationship between a carrier sensing time of the mobile station device and a transmission stopping time of the base station device; -
FIG. 6 is a diagram illustrating a processing for spatially multiplexing calls; -
FIG. 7 is a sequence diagram illustrating a processing for spatially multiplexing calls; -
FIG. 8 is a sequence diagram illustrating a processing for spatially multiplexing calls; -
FIG. 9 is a sequence diagram illustrating a processing for spatially multiplexing calls; -
FIG. 10 is a diagram illustrating a processing for spatially multiplexing calls; and -
FIG. 11 is a sequence diagram illustrating the multiple allocation processing of communication channels in a conventional mobile communication system. - Embodiments of the present invention will be described below with reference to the attached figures.
FIG. 1 is a diagram showing the configuration of amobile communication system 10 according to an embodiment of the present invention. As shown inFIG. 1 , themobile communication system 10 includes abase station device 12 which is connected to acommunication network 16 via a wired transmission line, and a plurality ofmobile station devices 14 which are connected to thebase station device 12 via wireless transmission channels. In addition to space division multiple access, themobile communication system 10 can also use time division multiple access (TDMA). -
FIG. 2 is a block diagram showing the configuration of thebase station device 12. Thebase station device 12 includes acontrol unit 20, astorage unit 30, awireless communication unit 40, and awired communication unit 50. For example, as shown inFIG. 10( a), thebase station device 12 multiplexes four time division channels in one TDMA frame having a predetermined time period, and further accommodates calls from at least twomobile station devices 14 per channel by spatial multiplexing. The same carrier frequency is used in each of the time slots. - As shown in
FIG. 2 , anadaptive array antenna 42 is connected to aradio unit 44. Theradio unit 44 has a transmission unit and a receiving unit; thisradio unit 44 controls theadaptive array antenna 42 by time division, and switches between transmission and reception. The transmission unit of theradio unit 44 has an up-converter, a power amplifier and the like; and converts signals input from thesignal processing unit 46 from baseband signals into radio-frequency signals, amplifies these signals to the transmission output level, and outputs the signals to theadaptive array antenna 42. The receiving unit of theradio unit 44 includes a low-noise amplifier, a down-converter, and the like; and converts the signals received by theadaptive array antenna 42 from radio-frequency signals into baseband signals, amplifies the signals and outputs the signals to asignal processing unit 46. - The
signal processing unit 46 performs a control relating to the formation of the directivity pattern, i.e., it separates, extracts and demodulates the spatially multiplexed signals received from the respectivemobile station device 14 that are input from theradio unit 44, and outputs these signals to theline interface 48. Thesignal processing unit 46 modulates transmission signals input from theline interface 48, and performs a control that produces signals weighted for spatial multiplexing so as to be transmitted to the desiredmobile station device 14, and outputs these signals to theradio unit 44. Thesignal processing unit 46 performs parallel processing signals of at least two calls that are spatially multiplexed on one time division channel. - The
wired communication unit 50 is connected to acommunication network 16 by a wired transmission line such as an ISDN line or the like, and is connected to thesignal processing unit 46 via acontrol unit 20; a plurality of signals (voice or data baseband signals) are exchanged between a plurality of communication lines and thesignal processing unit 46. - The
control unit 20 includes atransmission control unit 22, a channelallocation control unit 24, and a communicationchannel notification unit 28; and controls thebase station device 12 as a whole. Thetransmission control unit 22 performs a transmission control process that causes theradio unit 44 to transmit intermittently to themobile station devices 14. The channelallocation control unit 24 includes a slot for multiplexingselection unit 26; this channel allocation control unit selects a call and a time slot for spatial multiplexing, and controls the allocation of communication channels. The communicationchannel notification unit 28 notifies themobile station device 14 making a connection request for multiplex communications of the communication channel determined by the channelallocation control unit 24. Thecontrol unit 20 is constructed from a CPU, memory, and the like. - The
storage unit 30 includes a transmissionpattern storage unit 32 and a successful transmissionpattern storage unit 34; and stores transmission control information that is used in the transmission control processing performed by thetransmission control unit 22. For example, thestorage unit 30 is constructed from the memory of thecontrol unit 20. -
FIG. 10 is a diagram illustrating a process in which thebase station device 12 performs spatial multiplexing of calls from twomobile station devices 14 in a single time division channel.FIG. 10( a) shows a state prior to the spatial multiplexing of the calls. The channel relating to the slot 1 (hereafter referred to as “channel 1”) is used only for thecall 1 of the first mobile station device 14 (hereafter referred to as “PS1”), and the channel relating to the slot 2 (hereafter referred to as “channel 2”) is used only for thecall 2 of the second mobile station device 14 (hereafter referred to as “PS2”). Respective specified carrier frequencies are allocated to the respective channels. A description shall be provided with reference toFIG. 11 of a process for further allocatingchannel 1 already in use in communications bycall 1 to call 3 from the third mobile station device 14 (hereafter referred to as “PS3”) newly making a channel establishment request from this state. As a result of this process, the allocation state of the communication channels changes from the state shown inFIG. 10( a) to the state shown inFIG. 10( b). Below, for convenience, calls that are already in communication in communication channels for multiplexing will be referred to as “calls to be multiplexed,” and calls to which the communication channels are newly allocated will be referred to as “multiplex calls.” - In the state shown in
FIG. 10( a), PS1 is already in communication with the base station device 12 (hereafter referred to as “CS”) using channel 1 (S100). Here, when PS3 transmits a connection request signal (LCH establishment request signal) to CS (S102), CS determines a communication channel that is to be allocated to PS3. In the example shown inFIG. 11 , call 3 of PS3 is selected as a multiplex call in the channelallocation control unit 24, andslot 1 allocated to call 1 of PS1 is selected as a slot for multiplexing by the slot for multiplexingselection unit 26. The communicationchannel notification unit 28 notifies PS3 with information relating to thechannel 1 selected by the slot for multiplexing selection unit 26 (S104). Specifically, information including theslot 1 and the carrier frequency used in theslot 1 is sent to PS3 by the communicationchannel notification unit 28. Following the notification regarding the communication channel, CS stops the transmission of signals to PS1 already in communication on thechannel 1 for a predetermined time by control of the transmission control unit 22 (S106). On the other hand, when PS3 receives information relating to the communication channel (channel 1) from CS, PS3 performs a carrier sense on the communication channel (S108). Since CS stops transmission to PS1 while PS3 is performing the carrier sense, PS3 does not detect transmission signals to PS1 as interference waves. - When PS3 passes the carrier sense, PS3 transmits a synchronizing burst signal (synchronizing control signal) used for establishing synchronization to CS using the communication channel notified from CS (S110). CS resumes transmission to PS1 at the timing at which CS receives this synchronizing burst signal from PS3, or at a timing at which a predetermined period of time has elapsed after stopping the transmission to PS1 as preset by a timer or the like. When CS receives the synchronizing burst signal from PS3, CS transmits a synchronizing burst signal to PS3 as a response to this synchronizing burst signal (S112). The multiplexing to the
channel 1 of thecall 3 which is the multiplex call is completed at the timing at which synchronization is established between CS and PS3, and the state shown inFIG. 10( b) is obtained. Next, as a result of receiving the synchronizing burst signal from CS, PS3 judges that synchronization has been established, and transmits a communication signal to CS using the communication channel allocated by CS (S114). This communication signal may be an idle signal, or may be a significant signal such as voice, data or the like. CS also similarly transmits a communication signal to PS3 using the communication channel (S116). - In an actual SDMA mobile communication system, as described above, the timing at which a carrier sense is started and the time required for the carrier sense differ according to the type of the mobile station devices.
FIG. 5 shows the number of frames (frame period of 5 milliseconds) up to the start of a carrier sense from the time at which notification of a communication channel is received, and the number of frames required in order to perform carrier sensing for various types of mobile station devices. InFIG. 5 , for example, in the case of PS1, the number of frames from the reception of communication channel notification to the start of a carrier sense is 2, and the number of frames required in order to perform the carrier sense is 5; meanwhile, in the case of PS13, the number of frames up to the start of a carrier sense is 22, and the number of frames required in order to perform the carrier sense is 7. It is seen from these examples as well that the time at which a carrier sense is started and the time period required for the carrier sense vary greatly according to the type of mobile station devices used. Accordingly, in a conventional system, in order to allow any type of mobile station device to pass a carrier sense in a reliable manner, it is necessary to set the transmission stopping time at a fairly long period in CS. According to such an arrangement, a carrier sense can be reliably passed with a single transmission stoppage. However, if precedence is given to the pass of carrier sensing and the transmission stopping time is set at an excessively long time, the mobile station device side on which transmission is stopped receives no signals from CS that inherently should have been transmitted; accordingly, there is a risk that the mobile station device detects this as a frame error and initiates a handover. As a result, it becomes impossible to spatially multiplex calls of a plurality of mobile station devices on a single communication channel. - Accordingly in the
base station device 12 according to the present embodiment, as indicated by thetransmission stopping times 1 through 3 shown inFIG. 5 , spatial multiplexing of calls can be accomplished at any timing by repeating intermittent transmissions using various transmission patterns while suppressing the occurrence of frame errors in themobile station device 14 involved in a call to be multiplexed by shortening the respective transmission stopping times. Specifically, after notification of a communication channel for multiplexing to themobile station device 14 involved in the multiplex call, thetransmission control unit 22 according to the present embodiment performs the intermittent transmission of communication signals to the mobile station device involved in the call to be multiplexed that is already in communication on the communication channel. According to such an arrangement, the timing of a carrier sense and the timing of transmission stoppage tend not to match, so that the probability that a carrier sense will not be passed is increased; on the other hand, an increase in the frame error rate can be suppressed, and the initiation of handover can be prevented. - Furthermore, the
transmission control unit 22 may also read out any of the transmission patterns for intermittent transmission store in the transmissionpattern storage unit 32, and perform the intermittent transmission of communication signals to the mobile station device involved in the call to be multiplexed in accordance with this transmission pattern.FIG. 3 is a diagram showing an example of the transmissionpattern storage unit 32. As shown inFIG. 3 , the transmissionpattern storage unit 32 stores a plurality of transmission patterns for intermittent transmission in association with transmission pattern numbers. The intermittent transmission pattern may include information specifying the number of frames up to the stopping of the transmission of communication signals to themobile station device 14 involved in a call to be multiplexed after notification regarding a communication channel provided to themobile station device 14 involved in a multiplex call, and a time period for which the transmission is stopped. - Furthermore, the transmission pattern for intermittent transmission in cases where the
mobile station device 14 making the start request for multiplex communications has passed a carrier sense may also be stored in the successful transmissionpattern storage unit 34 in association with identification information for themobile station device 14. Moreover, in cases where a start request for multiplex communications is again made by themobile station device 14, the transmission pattern for intermittent transmission may be read out from the successful transmissionpattern storage unit 34 in association with identification information for thismobile station device 14, and intermittent transmission of communication signals may be performed to the mobile station device in communication using a communication channel for multiplexing in accordance with the transmission pattern.FIG. 4 is a diagram showing an example of the successful transmissionpattern storage unit 34. As shown inFIG. 4 , the successful transmissionpattern storage unit 34 stores transmission patterns for intermittent transmission in association with identification information formobile station devices 14. Furthermore, the successful transmissionpattern storage unit 34 may store transmission pattern numbers in the transmissionpattern storage unit 32 in association with identification information for themobile station devices 14. - Next, the spatial multiplexing processing of calls according to the present embodiment will be described with reference to
FIGS. 6 through 9 .FIG. 6 shows typical cases in which thebase station device 12 performs the multiple allocation of a multiplex call on a communication channel in use in communications.FIG. 6( a) shows a case in which thechannel 1 in use by thecall 1 is allocated to thecall 3 newly requesting a channel establishment.FIG. 6( b) show a case in which when thecall 3 newly requests a channel establishment, thechannel 2 in use by thecall 2 is multiple-allocated to thecall 1 using thechannel 1, after which theidle channel 1 is allocated to thecall 3.FIG. 6( c) shows a case in which the communication quality on thechannel 1 in use by thecall 1 has deteriorated, and thechannel 2 with good communication quality in use by thecall 2 is therefore multiple-allocated to thecall 1. - Below, in
FIGS. 7 through 9 , processing that is substantially the same as the processing inFIG. 11 will be indicated by the same symbols, so that a redundant description is omitted. -
FIG. 7 is a sequence diagram of the processing for spatially multiplexing thecall 3 on thechannel 1. As a result of this processing, the allocation state of the communication channels changes from the state shown inFIG. 10( a) to the state shown inFIG. 10( b) (orFIG. 6( a)). The processing shown inFIG. 7 is the same as the processing illustrated inFIG. 11 except for the stoppage of transmission to PS1 (S106) and the carrier sensing (S108). In the processing shown inFIG. 7 , after CS notifies PS3 of the information relating to channel 1 (S104), thetransmission control unit 22 retrieves one of the transmission patterns for intermittent transmission stored in the transmissionpattern storage unit 32, and performs the intermittent transmission of communication signals to PS1 in accordance with this transmission pattern (S200, S202). For example, in a case where thetransmission control unit 22 retrieves thetransmission pattern 1 from the transmissionpattern storage unit 32 shown inFIG. 3 , the transmission to PS1 is continued for one frame period following the processing of S104; subsequently, transmission to PS1 is stopped for a period equal to eight frame periods (S200). Afterward, thetransmission control unit 22 resumes transmission to PS1 (S202). In this case, PS3 performs a carrier sense at the timing of S202 in which transmission to PS1 is resumed, and transmission signals from CS to PS1 are detected as interference waves (S204). As a result, the carrier sense cannot be passed, and PS3 cannot make a start request for multiplex communications to CS. - In cases where the start request for multiplex communications from PS3 cannot be received even after a predetermined time preset by a timer or the like has elapsed, CS judges that the carrier sense of PS3 has failed. In this case, the transmission pattern for intermittent transmission to PS1 is changed, and the same processing as described above is performed again. Here, when the stopping of transmission to PS1 is repeated, the frame error rate rises in PS1, and a risk is presented that a handover may be initiated. Accordingly, in order to suppress the occurrence of frame errors in PS1, the stopping of transmission may be limited until a predetermined time has elapsed after the transmission has been stopped once.
- In cases where the transmission of communication signals to PS1 is again stopped in order to pass the carrier sense of PS3, the communication
channel notification unit 28 of CS notifies PS3 of information relating to the channel 1 (S104). Subsequently, thetransmission control unit 22 again retrieves one of the transmission patterns for intermittent transmission from the transmissionpattern storage unit 32, and performs the intermittent transmission of communication signals to PS1 in accordance with this transmission pattern (S206, S208). For example, in a case where thetransmission control unit 22 retrieves thetransmission pattern 2 from the transmissionpattern storage unit 32 shown inFIG. 3 , transmission to PS1 is continued for 12 frame periods (S206) following the processing of S104; then, transmission to PS1 is stopped for six frame periods (S208). Then, thetransmission control unit 22 subsequently resumes transmission to PS1. In this case, since PS3 performs a carrier sense at the timing of S208 when transmission to PS1 is stopped, no transmission signal from CS to PS1 is detected, and the carrier sense is passed (S210). When the carrier sense is passed, PS3 establishes synchronization with CS (S110, S112), and starts the transmission and reception of communication signals (S114, S116). Even if the carrier sense of PS3 again fails in S210, CS repeats a similar process while varying the transmission pattern for intermittent transmission to PS1 until the carrier sense of PS3 is passed. - Furthermore, in the abovementioned processing sequence, an example in which the stopping of transmission to PS1 is repeated is shown. However, it would also be possible to devise the system so that the stopping of transmission for calls in the same time slot is not repeated, by altering the slot for multiplexing or the like after a carrier sense has failed, in order to suppress the occurrence of frame errors in PS1. For example, in a case where PS3 performs a carrier sense in S204 of
FIG. 7 and CS judges that the carrier sense has failed, the communicationchannel notification unit 28 of CS sends information relating tochannel 2 in the LCH allocation of S104 to PS3 after a predetermined time has elapsed. Then, thetransmission control unit 22 retrieves one of the transmission patterns for intermittent transmission from the transmissionpattern storage unit 32, and intermittently transmits communication signals to the terminal (e.g., PS2) using the channel 2 (e.g., slot 2) in accordance with this transmission pattern. -
FIG. 8 is a sequence diagram of the processing for spatially multiplexing thecall 1 on thechannel 2. As a result of this processing, the allocation state of the communication channels changes from the state shown inFIG. 10( a) to the state shownFIG. 6( b). In the initial state shown inFIG. 10( a), PS1 is in communication with CS via channel 1 (S100), and PS2 is in communication with CS via channel 2 (S101). Here, when PS3 transmits a connection request signal (LCH establishment request signal) to CS (S102), CS determines a communication channel that is to be allocated to PS3. In the example shown inFIG. 6( b), call 1 of PS1 that is in communication viachannel 1 is selected as a multiplex call in the channelallocation control unit 24, andslot 2 allocated to thecall 2 of PS2 is selected as a slot for multiplexing by the slot for multiplexingselection unit 26. The channelallocation control unit 24 then performs a control for allocatingchannel 1 which is an idle channel to PS3 as a result of the moving of PS1 to channel 2. The communicationchannel notification unit 28 notifies PS1 of information relating tochannel 2 selected by the slot for multiplexingselection unit 26, and an instruction is given that the communication channel is to be switched fromchannel 1 to channel 2 (S212). In concrete terms, information including theslot 2 and the carrier frequency used inslot 2 is sent to PS1 by the communicationchannel notification unit 28. Below, the stoppage of transmission to PS2 (S214, S216) and the carrier sense performed by PS1 (S218, S224) have substantially the same processing content as the stoppage of transmission to PS1 (S200, S202) and the carrier sense performed by PS3 (S204, S210) inFIG. 7 except for the fact that the type ofmobile station devices 14 is different; accordingly, a description of this process is omitted. When PS1 passes the carrier sense in S224, andchannel 2 is multiple-allocated to PS1 (S226, S228), communication onchannel 2 is started between PS1 and CS (S230, S232). Consequently,channel 1 becomes an idle channel, and from S234 on, allocation of channels to PS3, including carrier sensing by PS3, is performed. -
FIG. 9 is a sequence diagram of the processing for spatially multiplexing thecall 1 on thechannel 2. As a result of this processing, the allocation state of communication channels changes from the state shown inFIG. 10( a) to the state shown inFIG. 6( c). The processing shown inFIG. 9 is processing in which the processing of PS3 is omitted from the processing shown inFIG. 8 ; accordingly, a description of this process is omitted here. - According to the base station device and control method for the base station device described above, the occurrence of frame errors caused by carrier sensing performed in space division multiple allocation can be suppressed, and the success rate of space division multiple allocation can be improved.
- Furthermore, the present invention is not limited to the embodiment described above. For example, in the embodiment described above, an example of a mobile communication system using both time division multiple access and space division multiple access is indicated. However, the present invention can also be applied to a system using only space division multiple access, or to a system combining some other multiplexing scheme with space division multiple access.
- Furthermore, the mobile station devices described above may include carrier sense timing notification means, and notify the base station device of their own carrier sense timing information (carrier sense start timing, time required for a carrier sense, or the like).
Claims (9)
1. A base station device which is capable of multiplex communications with a plurality of mobile station devices using space division multiple access on a communication channel at a specified carrier frequency, receives a start request for multiplex communications from the mobile station device in accordance with a presence or absence of another communication signal on the communication channel, and allocates the communication channel to the mobile station device that has made the start request in response to the start request, the base station device comprising:
transmission control means for performing intermittent transmission of communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices.
2. The base station device of claim 1 , wherein the transmission control means performs the intermittent transmission of the communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices, after notification of the communication channel is provided to the mobile station device that has made the start request.
3. The base station device of claim 1 , further comprising transmission pattern storage means for storing a plurality of transmission patterns for the intermittent transmission, wherein the transmission control means retrieves one of the transmission patterns stored in the transmission pattern storage means, and intermittently transmits the communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices, in accordance with this transmission pattern.
4. The base station device of claim 1 , further comprising successful transmission pattern storage means for storing the transmission pattern for the intermittent transmission performed by the transmission control means in association with identification information for the mobile station device that has made the start request, wherein
in a case where a start request is again made by the mobile station device that has made the start request, the transmission control means retrieves the transmission pattern stored in the successful transmission pattern storage means in association with identification information for this mobile station device, and intermittently transmits communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices, in accordance with this transmission pattern.
5. The base station device of claim 3 or 4 , wherein the transmission pattern includes information specifying a timing at which the transmission of the communication signals to the mobile station device already in communication on the communication channel among the plurality of mobile station devices is stopped, and a period for which the transmission is stopped.
6. The base station device of any one of claims 1 through 4, wherein
the transmission control means limits the stopping of the transmission of the communication signals on the communication channel until a predetermined period of time has elapsed after once stopping the transmission of the communication signals on the communication channel.
7. The base station device of any one of claims 1 through 4, wherein the transmission control means initiates transmission after once stopping the transmission of the communication signals on the communication channel, and stops the transmission on a communication channel differing from the communication channel on which the transmission of the communication signals was once stopped when the transmission is again stopped.
8. The base station device of any one of claims 1 through 4, wherein
the base station device is capable of multiplex communications with the plurality of mobile station devices using time division multiple access and space division multiple access;
the base station device comprises slot for multiplexing selection means for selecting any one of time slots already allocated to at least one of the mobile station devices other than the mobile station device that has made the start request as a slot for multiplexing that is allocated to the mobile station device that has made the start request; and
the communication channel is specified by the slot for multiplexing selected by the slot for multiplexing selection means and the specified carrier frequency.
9. A control method for a base station device which is capable of multiplex communications with a plurality of mobile station devices using space division multiple access on a communication channel at a specified carrier frequency, receives a start request for multiplex communications from the mobile station device in accordance with a presence or absence of another communication signal on the communication channel, and allocates the communication channel to the mobile station device that has made the start request in response to the start request, wherein
communication signals are intermittently transmitted to the mobile station device already in communication on the communication channel among the plurality of mobile station devices.
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JP2005-376534 | 2005-12-27 | ||
JP2005376534A JP4704909B2 (en) | 2005-12-27 | 2005-12-27 | Base station apparatus and control method for base station apparatus |
PCT/JP2006/325612 WO2007077763A1 (en) | 2005-12-27 | 2006-12-22 | Base station device and base station device control method |
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JP (1) | JP4704909B2 (en) |
CN (1) | CN101352067B (en) |
WO (1) | WO2007077763A1 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20080192644A1 (en) * | 2007-02-08 | 2008-08-14 | Yoriko Utsunomiya | Radio communication apparatus and radio communication method |
US20100103900A1 (en) * | 2006-12-08 | 2010-04-29 | Choong-Il Yeh | Beamforming method and device |
US20120307706A1 (en) * | 2010-02-05 | 2012-12-06 | Sharp Kabushiki Kaisha | Transmission device, reception device, wireless communication system, transmission control method, reception control method, and processor |
US20130084907A1 (en) * | 2010-06-22 | 2013-04-04 | Alcatel Lucent | Method and device for inter-cell interference coordination |
US20130208619A1 (en) * | 2010-11-16 | 2013-08-15 | Nippon Telegraph And Telephone Corporation | Wireless communication system and wireless communication method |
US20140241161A1 (en) * | 2011-09-30 | 2014-08-28 | Telefonaktiebolaget L M Ericsson (Publ) | Method and Apparatus for Controlling Data Transmission in a Communication System |
US11074799B1 (en) * | 2020-01-24 | 2021-07-27 | T-Mobile Usa, Inc. | Modular tracking device |
US11252031B2 (en) | 2019-11-20 | 2022-02-15 | T-Mobile Usa, Inc. | Coordinated management of IoT device power consumption and network congestion |
US11297568B2 (en) | 2019-01-18 | 2022-04-05 | T-Mobile Usa, Inc. | Location-based apparatus management |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6975867B2 (en) * | 2001-08-31 | 2005-12-13 | Sanyo Electric Co., Ltd. | Radio base apparatus, communication channel allocation method, and allocation program |
US6999771B1 (en) * | 2001-09-28 | 2006-02-14 | Arraycomm Llc | Channel assignments in a wireless communication system having spatial channels including grouping existing subscribers in anticipation of a new subscriber |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06334604A (en) * | 1993-05-24 | 1994-12-02 | Sharp Corp | Carrier sense system in tdma-tdd communication |
EP1286506B1 (en) * | 2001-08-07 | 2005-10-19 | Kabushiki Kaisha Toshiba | Wireless communication system and wireless station |
JP4137662B2 (en) * | 2003-02-14 | 2008-08-20 | 京セラ株式会社 | Communication control method, wireless device, portable terminal |
-
2005
- 2005-12-27 JP JP2005376534A patent/JP4704909B2/en not_active Expired - Fee Related
-
2006
- 2006-12-22 CN CN2006800494880A patent/CN101352067B/en not_active Expired - Fee Related
- 2006-12-22 US US12/159,087 patent/US20100027513A1/en not_active Abandoned
- 2006-12-22 WO PCT/JP2006/325612 patent/WO2007077763A1/en active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6975867B2 (en) * | 2001-08-31 | 2005-12-13 | Sanyo Electric Co., Ltd. | Radio base apparatus, communication channel allocation method, and allocation program |
US6999771B1 (en) * | 2001-09-28 | 2006-02-14 | Arraycomm Llc | Channel assignments in a wireless communication system having spatial channels including grouping existing subscribers in anticipation of a new subscriber |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100103900A1 (en) * | 2006-12-08 | 2010-04-29 | Choong-Il Yeh | Beamforming method and device |
US8068455B2 (en) * | 2007-02-08 | 2011-11-29 | Kabushiki Kaisha Toshiba | Radio communication apparatus and radio communication method |
US20080192644A1 (en) * | 2007-02-08 | 2008-08-14 | Yoriko Utsunomiya | Radio communication apparatus and radio communication method |
US9001724B2 (en) * | 2010-02-05 | 2015-04-07 | Sharp Kabushiki Kaisha | Transmission device, reception device, wireless communication system, transmission control method, reception control method, and processor |
US20120307706A1 (en) * | 2010-02-05 | 2012-12-06 | Sharp Kabushiki Kaisha | Transmission device, reception device, wireless communication system, transmission control method, reception control method, and processor |
US20130084907A1 (en) * | 2010-06-22 | 2013-04-04 | Alcatel Lucent | Method and device for inter-cell interference coordination |
US9351306B2 (en) * | 2010-06-22 | 2016-05-24 | Alcatel Lucent | Method and device for inter-cell interference coordination |
US9276652B2 (en) * | 2010-11-16 | 2016-03-01 | Nippon Telegraph And Telephone Corporation | Wireless communication system and wireless communication method |
US20130208619A1 (en) * | 2010-11-16 | 2013-08-15 | Nippon Telegraph And Telephone Corporation | Wireless communication system and wireless communication method |
US20140241161A1 (en) * | 2011-09-30 | 2014-08-28 | Telefonaktiebolaget L M Ericsson (Publ) | Method and Apparatus for Controlling Data Transmission in a Communication System |
US9532263B2 (en) * | 2011-09-30 | 2016-12-27 | Telefonaktiebolaget Lm Ericsson (Publ) | Method and apparatus for controlling data transmission in a communication system |
US11297568B2 (en) | 2019-01-18 | 2022-04-05 | T-Mobile Usa, Inc. | Location-based apparatus management |
US11252031B2 (en) | 2019-11-20 | 2022-02-15 | T-Mobile Usa, Inc. | Coordinated management of IoT device power consumption and network congestion |
US11881995B2 (en) | 2019-11-20 | 2024-01-23 | T-Mobile Usa, Inc. | Coordinated management of IoT device power consumption and network congestion |
US11074799B1 (en) * | 2020-01-24 | 2021-07-27 | T-Mobile Usa, Inc. | Modular tracking device |
US20210319680A1 (en) * | 2020-01-24 | 2021-10-14 | T-Mobile Usa, Inc. | Modular tracking device |
US11676469B2 (en) * | 2020-01-24 | 2023-06-13 | T-Mobile Usa, Inc. | Modular tracking device |
Also Published As
Publication number | Publication date |
---|---|
JP2007180856A (en) | 2007-07-12 |
CN101352067B (en) | 2012-04-04 |
WO2007077763A1 (en) | 2007-07-12 |
JP4704909B2 (en) | 2011-06-22 |
CN101352067A (en) | 2009-01-21 |
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